ABSTRACT Physical activity (PA) at a high intensity reduces motor symptoms and improves motor performance for persons with Parkinson Disease. Barriers to achieving the PA intensity include motivation, fatigue, depression, fear of falling and self-efficacy. Bicycling in a continuous and interval modes have been used to promote high intensity PA. Yet, some of those protocols are difficult to implement because they do not address the barriers of motivation and self-efficacy. In this study we propose a virtual reality (VR) bicycling system to address some of these barriers. Individuals screened for PA and depression will be enrolled in a two-day study. To determine if persons with Parkinson Disease exercise at a greater intensity (musculoskeletal and cardiovascular and pulmonary) in a VR-cycling versus a non-VR cycling environment we will test 60 persons with PD (HY Stages II-III) between the ages of (45-80), cycling both in a VR and non-VR conditions in both a continuous and interval modes. We will also collect using both quantitative and qualitative measures of enjoyment and perceived effort. Finally, we will ask participants to cycle under two immersion conditions (semi and fully) to determine which VR delivery mode yields the highest exercise intensity and enjoyment. Findings from this study will guide the formulation of a training study to test the efficacy of VR augmented cycling to reduce motor symptoms and improve motor performance and fitness of persons with PD.